Computer assisted graphic teleconferencing method and apparatus

ABSTRACT

An audiographic telephone conferencing system between a plurality of parties or users either directly connected or through a piece of apparatus known as a &#34;meet me bridge&#34; over voice grade telephone lines. Each user has a programmed personal computer which controls a programmable or &#34;smart&#34; modem, cassette recorder/player, and speakerphone. A protocol is implemented by the software, i.e. the computer program, in each of the computers which puts its respective modem in a listening mode to monitor the phone line at all times. The computer is further programmed and includes a memory for storing and transmitting graphics presently on hand to other user(s) via the modem during a teleconference or alternatively receive graphics from another user, or it can switch to an external graphics program to make new or modify existing graphic images. However, one is unable to speak on the telephone line while a graphic is being transmitted during a teleconference due to the fact that voice alternates with graphic transmissions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of applicants copending application Ser.No. 849,314 filed Apr. 8, 1986, which is now U.S. Pat. No. 4,656,654which is a continuation of application Ser. No. 598,751 filed Apr. 11,1984 now abandoned.

The invention described herein may be manufactured, used and licensed byor for the Government for governmental purposes without the payment tome of any royalties thereon or therefor.

REFERENCED MATERIAL

Reference is made to the microfiche Appendix which sets forth a computerprogram listing including that which is applicable to the presentinvention. Included is 1 microfiche containing a total of 21 frames.

FIELD OF THE INVENTION

This invention relates generally to telephone communications systems andmore particularly to computer enhanced telephone conferencing systemspermitting the sending or receiving of graphics to the connected partiesprior to or during a particular telephone conference.

BACKGROUND OF THE INVENTION

In multiperson conferences, most people's first choice for a conferencewould be a face-to-face meeting with all of the participants or parties.All conversations are then in real time but at a great deal of expense,particularly where participant travel is involved. One alternative toface-to-face meetings is a TV conference wherein participants go tolocal TV studios for an electronic "face-to face" meeting. TV meetingstend to lessen cost by reducing travel but studios equipped for TVconferencing are limited and facility rental might occasionally evenexceed actual face-to-face meeting costs. Still another alternativewould be a specially equipped conference room, e.g., with an electronicblackboard, that might be more readily available and at a lower costthan TV conferencing. While this eliminates face-to-face contact, twotelephone lines, one of which must be a dedicated high speed datacircuit, are usually required for a link-up at each site. Then there isthe well known telephone conference call which comprises a widely usedrelatively inexpensive way of conducting a conference. However,telephone conferencing provides a voice only system even though it iseconomical enough to permit each individual to have a regular telephoneunit.

Computer conferencing, although known, is usually limited to terminalproduced text communications with other participants via a central orhost computer. A relatively permanent transcript computer, thus allowingparticipants to enter or leave the "meeting" at uncoordinated times. Areturning conferee need only read the proceedings actually missed.Messages may be left for non-attendees. Computer conferencing offers buthas not yet realized the potential of using the computer itself as aninteractive participant, such as fetching data not previously retrievedand/or conducting real time analyses during the conference. While all ofthe above prior art systems are useful for the task intended, they lackone or more certain desirable but heretofore unavailable features.

Accordingly, it is an object of the present invention to provide animproved method and apparatus for implementing a conference via atelephone.

Another object of the invention is to provide facilities for recordingconferences, sending or receiving messages so that all parties need notbe simultaneously present.

Still another object of the invention is to provide an improved methodand apparatus for integrating graphics into a telephone conference.

A further object of the invention is to provide a method and apparatusfor implementing audio-visual teleconferencing on a real time or delayedbasis.

Still another object of the invention is to provide a method and meanswhereby computerized control of a telephone conferencing system permitsthe transmission and reception of graphics between the parties prior toor during a telephone conference.

SUMMARY OF THE INVENTION

Briefly, the subject invention comprises a computer enhanced telephoneconferencing system providing dial-up audiographic communicationsbetween a plurality of participants or users, each having a personalcomputer specifically programmed to control a programmable modem andtelephone apparatus such as a speakerphone, and with the parties beingconnected by voice grade telephone lines via direct connection, anoperator connection, a meet-me-bridge or other appropriate apparatus.The computer software is operable to control the speakerphone, turningit on and off at appropriate times to eliminate room noise during thetransmission or reception of color graphics during a telephoneconversation. Each modem is furthermore controlled by the computer to be"live", that is on-line in a silent receive mode status unlesstransmitting and thus operates to monitor the phone line at all times.The computer is furthermore programmed to ignore all signals on thephone line except when proceeded by one of a predetermined set ofidentification codes, indicating that a graphics related signal is beingtransmitted to another conference participant. The computer, moreover,is operable to control the reception of incoming signals from remoteusers and either display a graphic transmitted therefrom, retrieve anddisplay a graphic presently contained in a local storage, maintain thedisplay unchanged dial up a remote user, transmit a graphic thereto orrequest a graphic on hand in his local buffer storage to be displayed.Also when desirable one can switch to a companion graphics program tocreate new and/or modify existing graphics.

All users connected on the telephone line are in a parallel hook-up,i.e., all receive a transmitted graphic(s) simultaneously oralternatively, all hear voice communications simultaneously. All graphicimages and associated data, such as title and text description for eachgraphic image, moreover, can be bulk transmitted in an unattended mode,i.e., forwarded to and stored at a remote location. In this event,programmed procedures are provided for setting the order ofpresentation, transmitting only picture titles and causing simultaneousretrieval at all conferencing, i.e , user locations.

In addition to live, interactive conferencing, the system provides fordelayed conferences wherein users are not all simultaneously present andleave voice-graphic messages for each other on computer controlledcassette recording apparatus, also included in the system. Further, therecording apparatus provides a record of the entire voice-graphicsconference on a recording medium.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing as well as other objects and advantages of the inventionwill be more readily understood when considered in light of the detaileddescription to follow taken in connection with the accompanying drawingin which:

FIG. 1 is a block diagram broadly illustrative of an audiographictelephone conference system in accordance with the subject invention;

FIG. 2 is a block diagram illustrative of the apparatus required by eachuser in the system shown in FIG. 1;

FIG. 3 is a flow diagram providing an overview of the operationalsoftware included in each personal computer of the system shown in FIG.1;

FIG. 4 is a software flow diagram illustrative of the steps forinitializing each modem shown in FIGS. 1 and 2;

FIG. 5 is a software flow diagram for initializing the program variablesin each computer shown in FIGS. 1 and 2;

FIG. 6 is a flow diagram illustrative of the operational mode of oneuser's computer wherein a code for viewing a locally stored graphic isreceived from another user;

FIG. 7 is a flow diagram illustrative of the operational mode of oneuser's computer wherein a code is received for receiving and displayinga picture or graphic sent from another user; and

FIGS. 8 through 17 comprise a set of flow diagrams illustrative of tencomputer controlled operational sequences selectable by way of thekeyboard at each computer.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings and more particularly to FIG. 1, thesubject invention is directed to an audiographic teleconferencing systemand its method of operation whereupon a plurality of user apparatus 10₁,10₂, 10₃ . . . 10_(n) of n participants or users are interconnected overstandard voice grade telephone lines 12₁, 12₂, 12₃ . . . 12_(n) by wayof telephone connection apparatus 14 comprising either means for adirect connection, an operator connection or conference call connectionmeans such as a "meet-me-bridge". A meet-me-bridge is a well known pieceof telephone apparatus employing amplifying circuitry and which operatesto eliminate line drop in a telephone conferencing system connectionbetween parties.

Each user apparatus 10₁ . . . 10_(n) of the system shown in FIG. 1further comprises a computer 16 such as an IBM Personal Computer whichis programmed to operate in accordance with self contained software, tobe explained in detail subsequently. Each personal computer (PC) 16 isbidirectionally coupled to and controls the operation of a programmablemodem 18, such as a Hayes Smartmodem 1200, via a signal path 19including an input/output port, not shown. The PC also controls turn onand turn off of speakerphone type of telephone apparatus 20 and an audiocassette recorder/player 22 by means of power leads 21a and 21b. Therecorder/player 22 is adapted to provide a record of a particulartelephone conference at the time it is in progress or recordaudiographic messages in an unattended mode.

Before considering the invention in any further detail, however, itshould be pointed out that the system of the present invention operateswith a computer protocol where no "handshaking" is required forinteraction between the n participants hereinafter referred to simply asusers, due to the fact that when the system is in operation, all of thecomputer controlled modems 18 are silent, i.e in a receive mode unlessthe respective personal computer 16 orders it to transmit graphicinformation to one or more other users. Accordingly, any number of thecomputers 16 in the network of FIG. 1 can receive the same digitalinformation from another user computer simultaneously via their modems18, the only constraint being that the user(s) are unable to hear eachother speak during the transmission of a picture, hereinafter referredto as a graphic, in the event that visual information is to betransferred between users during a telephone conference. In someinstances, the visual information is transmitted to one or more otherusers or parties prior to a telephone conference. In such instances, itis entered into the user's recorder/player 22 and thereafter retrievedand displayed during the conference.

This now leads to a consideration of FIG. 2 which is intended to furtherdisclose the details of one of a plurality of identical user apparatus10₁ . . . 10_(n). As shown in FIG. 2 each personal computer 16 iscomprised of a keyboard 21 joystick 23, and videocamera device 25, avisual display unit 24 including a cathode ray tube (CRT) and two diskdrive units 26, comprising a floppy or hard disk drive unit containing adisk, not shown, all of which couple to a system's unit 28 which in anIBM PC includes a digital memory 30 and at least one serial input-output(I/O) port 32, a game port 33, one parallel I/O port 34 and a digitizingboard 35. When desirable, other input devices such, as "mouse" and lightpen can be utilized. For example, a mouse shown by reference numeral 27can be connected to the system unit 28 via the same input port, notshown as the keyboard 21. A light pen would be coupled in parallel withthe joystick to the same port 41. The memory 30 includes a main memorysection 36 which, among other things, stores a computer programcomprising a sequence of instructions in the form of an operational codewhich is further set forth in referenced Appendix and is outlined in theflow charts depicted in FIGS. 3 through 17. The memory 30 also includesa video display buffer section 38 which is bi-directionally coupled tothe dual disk drive unit 26 via data bus 40 and to the video displayunit 24 by means of the digital data bus 42. The game port 33 is showncoupled to the main memory section 36 via the data bus 41 while thedigitizing board is coupled thereto by means of data bus 43. The serialI/O port 32 is coupled to the main memory section 36 by bus 44 andoperates to couple the main memory section to the programmable modem 18.The parallel I/O port 34 couples to the main memory by bus 46 forcontrolling the operation of a multiposition power relay 48 whichactivates or deactivates speakerphone 20 and/or cassette recorder 22 atappropriate times.

In operation, each personal computer 16 is programmed to initialize itsrespective programmable modem 18 into a listening mode which will thenoperate to monitor the phone line 12 at all times. The computer 16 isfurther programmed to monitor all signals and execute authorizedcommands proceeded by an identification code which, for example,indicates that the following signal is a graphic image signal whereuponthe computer 16 turns off the speakerphone 20 and graphic imageinformation will either be transmitted to or received from anothercomputer 16 or responds to a command to display graphic images currentlyin storage and thereafter displayed on the video display unit 24. Thecomputer operation of the associated modem 18, moreover, requires onlyhalf of the available bandwidth to transmit or receive graphics via therespective modems 18 over a voice grade telephone line 12. This providesfor possible use of twin transmitters or receivers, not shown to doubletransmission rates and thus reduce transmission time by one half.

In order to fully understand system operation, however, one mustconsider the software, i.e , the computer program, contained in each ofthe personal computers 16 in order to make the system operate asintended. Pursuant to this, the following flow charts as disclosed inFIGS. 3 through 17 will be considered with reference to one of theparticipants being considered a local user (LU) with the otherparticipants being considered remote users (RU).

Accordingly, and now referring first to FIG. 3, disclosed thereat is anoverview of the operation of each user equipment. When a local user (LU)wants to use the system, he must first turn on his computer 16 asindicated by reference numeral 56. Thereafter the computer initializesor "boots up" the program which comprises a set of initializationstatements that prepare the program for execution. The computercontrolled steps include initializing the modem 18, the steps of whichare shown in FIG. 4 by reference numeral 58, initializing the programvariables 60, the steps of which are shown in FIG. 5 and a display of aninitial or "Main Menu" as indicated by step 62. The Main Menu consistsof five user options which are set forth in the following Table I andwhich are selectable from the user's keyboard 21 (FIG. 2).

TABLE I MAIN MENU

1. Connect to an Incoming Call From Remote User(s)

2. Dial a Call To Remote User(s)

3. Switch to Companion Graphics (Army Graphics)

4. Transmit a full library and index of graphics To Remote User(s)

5. Receive a full library and index of graphics From Remote User(s)

By selecting option No. 1, the local user connects to an incoming callfrom a remote user as indicated by step 64. By option No. 2 the localuser automatically dials a remote user telephone either directly orthrough the bridge 14 per reference numeral 65 while option No. 3transfers to a Companion Graphics program stored along with the subjectprogram in his personal computer 16 and which is shown by referencenumeral 66.

Option No. 4 permits a user to transmit an entire collection or libraryof graphic images one after another without pause as shown in step 67.Finally, option No. 5 permits a user to automatically receive and save acomplete library of graphics including the index information, i.e.,graphic name and description as shown in step 68.

Further as indicated in FIG. 3, the two option steps 64 and 65 ofconnecting to an incoming call or dialing a remote user telephonepermits an "escape" from either operational sequence through thekeyboard 21 whereupon depressing of a designated "Escape" key causes theprogram to revert back to the display of the Main Menu as evidenced bystep 62. In the event that a "Switch To Companion Graphics" is selectedfrom the keyboard 21, the program immediately exits to this graphicsprogram and terminates there as evidenced by the step 70.

In the event that preparation for a formal presentation is desired, afacility is further provided whereby the presenter can have his personalcomputer 16 automatically call all other participants, i.e. remoteusers, and transmit an entire library of graphics in advance of actualusage as shown in step 67. Similarly, if this full library transmissionmode is to be employed, all remote user recipients are required to leavetheir unattended personal computers in a storage mode which is initiatedvia the fifth Main Menu option "Receive" (step 68). This mode comprisesputting the remote user's personal computer 16 into an auto-answer modeto accept and store a complete library of graphics including indexinformation without human attention.

Assuming that either option No. 1 or No. 2 of connecting to an incomingcall or dialing a remote user telephone is selected, a subroutinewhereby the display of a "Standard Menu", as shown by reference numeral72, occurs. The Standard Menu consists of ten options selectable fromthe keyboard 21 as set forth in the following Table II.

TABLE II STANDARD MENU

1. USE--Retrieve Graphic From Storage To Screen--(FIG. 8)

2. SAVE--Store New Graphic (Screen to Disk)--(FIG. 9)

TABLE II

3. TRANSMIT--Transmit Graphic On Screen To Remote User--(FIG. 10)

4. VIEW--Request Remote User To Retrieve Graphic From His Storage To HisScreen--(FIG. 11)

5. NEXT PICTURE--View Command For Next Appropriate Graphic as arrangedin the Index--(FIG. 12)

6. PREVIOUS PICTURE--View Command For Previous Appropriate Graphic asarranged in the Index--(FIG. 13).

7. INDEX--Display title and description Of All Stored Graphics--(FIG.14)

8. GRAPHICS--Selects "External Graphics" Program--(FIG. 15)

9. TAB--Display Or Suppress Display Of Standard Menu--(FIG. 16)

10. ESCAPE--Abort And Return To Main Menu--(FIG. 17)

Along with the display of the Standard Menu, a main program loop isentered, as shown by reference numeral 74, which operates tocontinuously check the modem 18 or the keyboard 21 for a command whichinvolves either receiving a view "V" code or a transmit "T" code from aremote useras evidenced by steps 76 and 78 or executes per step 80, oneof the ten selectable Standard Menu options from the keyboard 21. Inorder of preference the main program looks first to the keyboard 22 andthen to the modem 18. The receive "V" code and "T" code operation isfurther disclosed in the flow charts of FIGS. 6 and 7, respectively,while the operation of the Standard Menu options is set forth in theflow charts shown in FIGS. 8 through 17.

It is to be noted that the two operations of receiving the "V" and "T"codes permit a return, i.e. an "escape" route 81 back to the StandardMenu and the main program loop steps 72 and 74 as referenced by ESCAPE#2 shown in FIG. 3. This escape is provided by depressing a designated"Escape" key on the keyboard 21. However, while the Standard Menu isdisplayed and prior to or during the display of the Standard Menu (step72), an escape route 79 back to the display of the Main Menu (step 62)is provided by depressing the "Escape" key, in which case ESCAPE #1 isprovided back to the Main Menu display shown in Table I.

Considering now the operational software in further detail, reference isnow made back to the first sequence of instructions following the turnon of power (step 56) which involves the initialization of the modem 18.This is shown in FIG. 4. The first thing that is done is to open acommunications port, namely the serial I/O port 32 (FIG. 2) whichconnects the modem 18 to the Main Memory section 36 of the computer 16.This is shown in FIG. 4 by step 82. The port 32 is initialized with datato be transmitted using eight bits of data with no parity bits and twostop bits. Further the port 32 is set up so that two control lines, notshown, will be ignored, namely, the "clear to send" (CTS) line and the"data set ready" (DSR) line. This is indicated in FIG. 4 by referencenumerals 84 and 86. Once port 32 is initialized, a command is sent tothe programmable modem 18 to set several parameters, the first of whichis to ignore the carrier from a remote user modem 18 as indicated bystep 88. This means that no matter whether the local user modem 18 hearsthe remote carrier or not, it is to stay "on line", i.e. connected tothe telephone line 12. The second parameter is to turn off thetransmitter section of the modem, which includes both a transmittersection and a receiver section, not shown, as well as an input databuffer, and turn on the receiver section as indicated by referencenumerals 90 and 92. It should be pointed out that once the receiversection is turned on, it is never turned off but remains "alive" as longas the system is active and the computer 16 is turned on. Next a commandis issued which turns off modem echo as evidenced by reference numeral94. This suppresses result codes from local user's modem 18 so that themodem will not echo back characters that are transmitted to it from aremote user modem 18 when it is on line. Additionally, it suppressesinternal result codes from being transmitted from the local user modem18, that is, ordinarily when a command is sent to the modem it will echoback to the remote user modem a result of the code indicating whathappened with the command it has received. Next a parameter is set (step96) which turns on the modem speaker, also not shown, integral with themodem 18, so that it will be on until it is commanded otherwise, such aswhen the local user is connected to a remote user. Following this, aparameter sets the guard time for an "escape" sequence sent to themodem. This is shown by reference numeral 98. The escape sequence isrequired to switch the local user modem 18 from being on line with aremote user computer 16 to being in the command state when commands maybe sent to change its condition. The guard time is the amount of pausethat must surround a particular escape sequence.

Finally the local user modem 18 is placed in a mode in which it willtransmit and receive on the same frequency as shown by step 100. This isimportant to this invention in that it has the effect of restrictingmodem operation to one half the total bandwidth available and thuspermits the computer 16 to operate pairs of transmitters or receivers tosend or receive pictures or graphics transmitted over the voice gradetelephone line 12. When only one modem (single transmitter and receiverpair) is used, only half the bandwidth is actually used. The lowerfrequency half is selected because this part of the bandwidth providessomewhat more reliable communications than the high frequency part.

After the modem 18 of the local user is initiated, a series ofstatements are next executed which sets certain program variables to beused in the respective program of the local user's personal computer 16.This is disclosed in FIG. 5 and which is entitled "Initialize ProgramVariables". First of all, a set of instructions are executed to set upthe screen width of the local user video display 24 which includes acolor CRT, now shown. This is indicated as step 102. This set ofinstructions defines the screen to be of a width, for example, of 40characters, that is, it will show a 40 character display extending fromone side of the screen to the next. When desirable the screen width canbe set to 80 characters, depending upon the needs of the user.

Following this, the entire screen of the video display 24 is cleared asindicated by the "Clear Screen" step 104. Then parameters are set, asevidenced by reference numeral 106, designating the desired foreground,background, as well as the default colors for a color picture on theCRT. A parameter is next initialized which will set the maximum numberof pictures, i.e. graphics, which can be saved in the form of an indexfile on the disks in the dual disk drive unit 26 (FIG. 2). This is shownby reference numeral 108 and for the basic embodiment of the program,the quantity is set to be 30 per "library" with a directory limit of 30libraries. Next, a drive designation for graphic storage is set. This isshown by reference numeral 110, and for the embodiment of the inventionshown in FIGS. 1 and 2, it comprises the dual disk drive 26. A flag isthen set, as indicated by step 112 which indicates within the codewhether the program executing is the internal program of the computer 16or the Companion Graphics package which can be accessed through thelocal user keyboard 21. The next two instructions (steps 114 and 116)set up the area that will be used for saving the part of any graphicswhich would be covered by a menu, used during program execution. Theprogram menus are stored in the last four lines of a twenty-five linedisplay of the video display 24. This area of the screen is initializedto the selected background color and then copied into a local array(modem input buffer) which will be used for storing the section of thescreen when a graphic is received. Along with this a flag is set whichindicates whether or not the Main Menu is correctly being displayed andaccordingly is initially set to be "true".

The final set of statements 118 and 120 executed in the program variableutilization section of the code defines the addresses in the videodisplay buffer section 38 of the computer memory 30 which will be usedwhen the entire contents of the buffer previously loaded from the diskdrive unit 26 are transmitted to a remote user over the telephone line12.

In the basic embodiment of the program, the CRT display has a minimumresolution of 200 horizontal lines. These graphic image lines are storedor defined by a section of the computer's Main Memory section 36. Duringthe transmission of an entire picture, defining a particular graphicover the phone line 12 this set of lines is divided up into 100 segmentseach of which will contain the information for two or more completelines across the screen of a remote user's video display 24. Theinitialization process consists of computing and storing in local arraysthe addresses in the video display buffer of each of the 100 validsegments for use during transmission or receipt of an entire picture.Invalid segments are rejected and replaced with the default backgroundcolor. This process is indicated by reference numeral 118 of FIG. 5.Finally, a program pointer is set as evidenced by reference numeral 120,which sets the pointer to the first graphic (picture No. 1) in thegraphic storage index. As referred to earlier, and following theinitialization steps 58 and 60 (FIG. 3), the next procedure executedcalls a routine 62 to display the Main Menu (Table I) with a flag beingset indicating that this menu is being displayed. The local user maymanually turn on his speakerphone 20 at any time.

Again recapitulating, the first choice available by this Main Menu(Table I) is to connect the local user modem 18, i.e. bring the modem online, in the case where a phone connection has already been establishedwith one or more remote users. The second choice is to employ the localmodem 18 itself to dial the phone number of a remote user or in the casewhere a conference bridge 14 as shown in FIG. 1 is being used, thenumber of the bridge. These generate Connect (C) and Dial (D) commands,respectively. The third choice is to switch to a Companion Graphicsprogram such as a separately provided Army Graphics program while thefourth and fifth choice involves transmitting and receiving graphiclibraries. The local user is then asked to make a choice between thefive. If the first option is chosen, the program will immediately putthe local user modem 18 on line using a command which causes it to usethe same frequency when transmitting and receiving hereinafter calledthe "answer mode". After putting the modem 18 on line, the programbranches to a display routine (step 72) of the Standard Menu (Table II)which is displayed in the lower portion of the video display provided bythe CRT of the display apparatus 24.

If instead of the "C" command of option No. 1 of the Main Menu the localuser has chosen the second option a "D" command is initiated and theprogram goes into a dial routine which executes that command. The dialroutine is contained within a loop which is executed until either asuccessful connection is made to a remote user, for example, via thebridge 14 (FIG. 1) or the local user aborts the attempt. The firststatements within the loop cause the local user modem 18 to hang up incase it should be on line at this point, i.e., when the local userbegins the dialing sequence. Also text is printed on the CRT screen ofthe LU video display 24 requesting the local user to supply a phonenumber which is to be dialed. The local user, moreover, has the optionof specifying pulse dialing instead of the default which is tonedialing. The local user is also offered the option of introducing onesecond delays at arbitrary points in the phone number. These are usedwhen dialing through a PBX system in which a digit must first be enteredto get an outside line and the remainder of the phone number is thenentered. After printing this information on the CRT screen, the programwaits for the local user input via the keyboard 21. If that input shouldhappen to be actuation of the "Escape" key on the keyboard 21, theprogram aborts the attempt to dial a remote user and returns to the MainMenu (step 62) via the ESCAPE #1 route 79 shown in FIG. 3 which againprovides the five options indicated by Table I

If a phone number is now entered by the local user, a command string isset up to cause the modem 18 to dial the phone number and then return tothe command state rather than going on line. Also in this string is acommand to the local user's modem which will force it to be in theanswer mode when connection is made. The reason for this is the same asdescribed above with respect to the "C" command. After the modem 18 hasbeen commanded to dial the telephone number, the program enters a briefdelay loop and then clears the lower section of the local user's CRT andprints the question "Should the number be dialed again? Yes or No". Ifthe local user hits the "Escape" key on the keyboard 21, then the modem18 is commanded to hang up and a return is made to the Initial Menuoptions (step 62). If the user, however, replies to the questionentering "Yes", then the loop inside of the dial procedure is repeated.That will bring it down through the logic that has just been described,the first step of which is to hang up. Alternatively, if the local userdoesn't press the "Escape" key and doesn't say "Yes", but enters "No" onthe keyboard 21 indicating that he does not want to dial the phonenumber again, the modem 18 is put on line and its speaker is turned off.A flag which indicates whether or not the Main Menu is to be displayedis set to "False" and a return from the dial procedure is executed.Finally, if the local user selects the option requesting option No. 3 ofthe Main Menu which requests External Graphics, then all local files ofthe computer 16 are closed, the external Companion Graphics program isrun and the internal program of the computer 16 exits (step 70).

Once a successful connection is made to a remote user, however, thecomputer program of the local user computer 16 enters its main loop(step 74) which is executed from now until the "Escape" key on thekeyboard 21 is hit and consists in first looking for a local input fromthe keyboard 21 which would designate one of the commands available onthe Standard Menu (Table II) at this point. The commands available are"Use", "Save", "Transmit", "View", "Next Picture", "Previous Picture","Index", "Graphics", "Tab" and "Escape". The functions associated withthese commands are set forth in the flow charts shown in FIGS. 8 through17.

Assuming for the moment, however, that no local user keyboard input hasbeen received, the main program loop (step 74) then checks to seewhether any incoming characters have been received from a remote usercomputer 16 via the modem 18, for example, either a "V" code or a "T"code. The local user program calls a routine which checks the inputbuffer of the local user modem 18 to see if any characters are present.Since the receiver section for the modem 18 is always active, i.e. "on"following initialization, it is likely that characters have beenreceived; however, such characters are most likely erroneous onesconstructed from the sound of user's voices for example. Accordingly,the first thing the routine does is to see if there are at least fivecharacters in the modem's input buffer. If not, it returns immediatelyto the main program loop of step 74 (FIG. 3).

If, on the other hand, there are at least five characters in the inputbuffer of the modem 18, the routine goes into a loop which retrievescharacters from the input buffer in groups of five. Each group of fivecharacters is then checked to see if it, for example, consists of fiverepetitions of the letter "V" or five repetitions of the letter "T". Ifeither of these two patterns is detected, then execution continues asshown by the flow diagrams shown in FIGS. 6 or 7; otherwise, controlreturns to the main program loop (step 74) checking for keyboardentries.

Considering now first that a five character pattern consisting of theletter "V" has been detected, reference is now made to FIG. 6 whereinstep 122 indicates that a routine is called which handles an incoming"View" command for local user viewing of a specific graphic alreadystored in his dual disk drive unit 26. The local user speakerphone 20 isturned off as indicated by reference numeral 124 followed by aninitialization of a local storage array in Main Memory 36 (FIG. 2)having the ability to contain twelve data set names followed by aclearing of the CRT display 24 and an internal flag is set to "true"which indicates that a new data set name is required. This routine iscomprised of a loop consisting of two portions depending upon the answerto a query 126 made regarding the presence of the specific graphic inthe local user index. Thus in the loop, incoming graphic names areinstalled in the empty array and the loop proceeds from the first entryto the twelfth entry and compares each new name to all previous names inturn. If the current name is not the same as any previous entry, thenthe loop continues looking for subsequent entries. If a single match isdiscovered, then it is assumed that this is the true graphic name thatis required and at that point power to the local user speakerphone 20 isturned back on as indicated by reference numeral 128 and the data setname is placed in a procedure 130 that loads the video display buffersection 38 of the memory 30 from the disk drive 26 and the graphic isgenerated (step 132) on the CRT of the local user's video display 24.The lower portion of the display is stored in an internal array so thatthe Standard Menu (Table II) may be displayed without losing any data.The modem's input buffer is then cleared and the Standard Menu (TableII) is redisplayed if the flag to display the menu says that it shouldbe done and the procedure returns to the main program loop via ○2providing an escape, i.e. ESCAPE #2, back to steps 72 and 74 as shown inFIG. 3 If it is found that the graphic that is commanded by the remoteuser to be viewed is not present in the index, the speakerphone isturned on in step 134 and a message is displayed to the local user, perstep 136, advising him that the graphic is not on hand, and theprocedure returns back to the Standard Menu via ○2 at which time theremote user can, if desired, transmit a "T" code which now leads to aconsideration of FIG. 7.

The "T" code is used by the remote user to transmit the contents of hisscreen buffer to the local user. If five repetitions of the letter "T"are detected by the local user, then another routine is called to handlethe incoming "T" code as indicated, in FIG. 7, by reference numeral 138which is a command to handle the contents of a graphic which istransmitted from a remote user. Power to the speakerphone 20 is turnedoff, per step 140, and a routine 142 clears the local user's displayscreen or CRT and sets an internal flag indicating that graphic data isbeing received in segments preceded by header data consisting of fiveconsecutive zeros. If a zero is found, the next byte is checked to seewhether it also contains a zero. If it does, then subsequent bytes areexamined until a non-zero value is found. This value is taken to be asegment number and a flag indicating that a segment header is needed isthen set to "false". The program logic will then remain in loop lookingfor zeros until two successive zeros are found or until 1600 attemptshave been made to retrieve the character from the input buffer of thelocal user modem 18. If there is none available, the entire routine willterminate its execution and control is returned to the main program loopvia ○2 after the local user's speakerphone 20 has been turned on by step144.

Assuming that the appropriate header data is detected, the number of thesegment is used to obtain the address of the particular segment in thelocal user modem buffer memory. In the preferred embodiment, all dataare encoded or compressed before transmission. In one case the data areinterpreted as byte pairs, the first byte containing a count and thesecond one a bit pattern consisting of the color of four pixels. Eachbyte pair is expanded by copying the pattern byte the indicated numberof times into the video display buffer memory section 38 (FIG. 2) up tothe limit of the amount of memory required to display a particularsegment. After all the bytes of the segment have been written into thedisplay memory 38, a flag indicating that the signal header is requiredis set to "True" and processing continues as in the first half of thisroutine. The use of segmented transition in this way has the effect ofrestricting any data error in the transmission to a single pair of lineson the screen. Segments with out of sequence segment numbers arerejected entirely. When the main loop in this procedure times out, whichis about one second of silence on the part of the modem, then the lowerportion of the CRT screen of the video display 24, which will be coveredup by the menu that is displayed, is stored in the local array andcontrol returns to a routine which turns the speakerphone 20 back on asindicated by reference numeral 144 and then returns to the main programloop via ○2 .

Consider now the condition where a local user keyboard entry is made onkeyboard 21 as indicated by step 80 (FIG. 3) where one of the tenStandard Menu options set forth in Table II has been selected prior to areception of any "V" "T" code from a remote user. Selection of any oneof these options generates a command for execution of the specificfunctions now to be described.

The "Use" and "Save" commands are designed to locally retrieve from andstore graphic images in the local user's disk drive unit 26. The"Transmit" command takes whatever is currently on the CRT of the videodisplay 24, i.e. the contents of the video display buffer section 38 inthe main memory 30 and transmits it preceded by a "T" code over thetelephone line 12 to remote user(s) connected via the telephone systemand constitutes the complement of the receive "T" code step 78 shown inFIG. 3. The "View" command takes an argument from the local user eitheras a number or the name of a graphic in his disk storage unit 26 andsends it as "V" code to designated remote users for them to retrievethat same graphic from their own RU disk storage means 26 and display iton their respective remote user video display units 24 and comprises thecomplement of the receive "V" code step 76 of FIG. 3 The "Next" and"Previous" commands coordinate with an index file that refers to thefollowing or previous graphic displayed by the local user which is thencoupled with a "View" command for the appropriate graphic to bedisplayed by the remote user(s). The "Index" command displays a list ofall the locally stored graphics on the local user video display 24 andallows the local user to either delete pictures from the index file orto renumber the pictures as desired. The "Graphics" command allows thelocal user to switch to the aforementioned Companion Graphics program.The "Tab" is the command used to reveal or suppress the display of theStandard Menu, while the "Escape" command is used to abort the mainprogram loop and return the user to the Main Menu (Table I) via ESCAPE#1, i.e. route 79, shown in FIG. 3 or to the Standard Menu (Table II)via ESCAPE #2, i.e. route 81.

The "Use" and "View" commands require that the local user indicate whichgraphic is to be displayed on his video display 24. The "View" commandalso requires the local user to indicate which picture or graphic is tobe shown simultaneously on all of the remote user CRTs. These twocommands have a short code form in which the number of the desiredgraphic can be entered immediately following the selection of the "U" orthe "V" key on the keyboard 21 and the appropriate logic to handle sucha command is included in the main program loop. Essentially what is doneis that the incoming characters from the local user are collected in alocal string until a "carriage return" is observed. At that point thecollected string is analyzed to see if its last few characters were in apicture number or not. If they were a picture number, that number isplaced in another local variable which is checked by "Use" and "View"routines when they are called. The main program also contains logic tochange any incoming characters to upper case.

Since the "Index" file is used with many different commands, a wordabout this file is in order. It basically consists of a text file whichhas as entries the data set name for each graphic or picture, a userdesignated descriptive title which is optional, and a predeterminednumber of parameters indicating the foreground and background colors forparticular graphic. Routines are included in the control program to readthis index file from the disk included in the disk drive unit 26, towrite it to the disk drive unit, and to scan it looking for a particulardata set name. There are also routines to renumber and delete graphicswhich will be described subsequently.

Considering now in greater detail the Standard Menu options of Table II,reference will now be made first to FIG. 8 which discloses the "Use"routine. Accordingly when the local user selects the "U" mode on hiskeyboard 21 by typing in the letter "U", which is indicated by step 146,the main program checks to see whether or not a number of a graphic wasincluded in the command. If it was, the index is retrieved and the dataset name of the graphic at that number is placed into a variable. If theuser did not include a number, the picture name variable is set to beempty. If the picture name variable is empty, the message is printed inthe menu area asking the local user to enter the name or the number ofthe picture desired 148. After the required information is obtained, itis checked to see whether it is an "escape" character. If it is, theprocedure is exited back to the Standard Menu step 72 (FIG. 2) via ○2 .

If the input data from the user is a number, then the entry in the indexis used to obtain the data set name stored there. If the input data is aname, then the name is used in a scanning routine. It is to see whetheror not the name occurs in the index. Next a query is made as indicatedby step 150 to determine whether or not the required graphic or pictureis in the index. If the graphic is in the index it is loaded to thelocal user's video display buffer 38 from the disk drive 26 and read tothe CRT of the video display unit 24 as indicated by steps 152 and 154.If the graphic is not in the index, then a scanning routine is called tosee whether or not that name or number occurs in the index. If there isno picture by the name entered, a message to that effect is displayedand the local user is asked whether or not he wishes to review the indexof the graphics that are saved on the index file immediately asindicated by step 156. If the user hits the "Escape" key or indicates"No", the routine is exited back to the Standard Menu display via ○2 .If the user indicates affirmatively that he wishes to review the index,then the entries from the index file are displayed in the menu area insequence as indicated by step 157 and can at any point choose an entrytyping in a number (step 158) and which will be used for furtherprocessing. This search is circular so that when the end of the list ofgraphics is reached on the next file the first entry is again shown onthe screen. Finally when it has been determined which graphic the localuser desires, a binary loaded instruction which is included in step 152is included in the programming language and is invoked to load the datafrom the disk file into the video display buffer 38. This has the effectof displaying the graphic on the local user's screen. It should be notedthat with the "use" command, no data is transmitted using the modem andall of the remote users will be unaware that the local user is bringinga different picture up on his display.

Considering now FIG. 9, when the local user initiates a "Save" commandby typing "S", for example, on his keyboard 21 as evidenced by step 160,the graphic name variable is set to "empty", indicating that theidentity of the graphic that is to be saved in the index file is unknownand the procedure that is used to save the video display buffer iscalled which asks the local user to enter a name and descriptive titleof the graphic. This is indicated by step number 162. During either step160 or 162, the local user can hit the "Escape" key which would abortthe procedure and return to the main program loop (step 74) via ○2 .Once the name and title are known, the index is retrieved from the localuser's dual disk unit 26 and is scanned in order to determine two thingsas indicated by the queries 164 and 166. The first query 164 is whetherthe picture name already exists, meaning that it is in use, and secondly166, if it doesn't, whether there is an empty slot in the index whichcan be used to store the particular graphic information. If the graphicname exists, the user is informed that this is the case and is askedwhether he wishes to replace the current graphic name with a new one.This is shown by reference numeral 168. If the reply is in the negativeor the user hits "Escape", the character of the routine is aborted andthe program exits back to the Standard Menu (step 72) via ○2 . If,however, the reply is affirmative, then the slot in the index is the onethat will be used when the particular grahic is stored. If the graphicdid not already exist in the index and there is no room in the index fora new entry, the user is advised of this fact and is asked whether hewishes to delete any of the graphics that are currently stored in theindex. This is shown by reference numeral 170. If the local user repliesin the negative or enters "Escape", the routine is aborted and exits viaESCAPE #2 back to the Standard Menu. Otherwise another routine isentered as shown by reference numeral 172 which allows the user todelete pictures after which the routine exits back to the Standard Menudisplay via ○2 . In the "delete" routine 172, each entry from the indexis shown in succession on the user screen and if the user hits the "D"character, then the graphic will be deleted. If, however, the user hits"carriage return", the next entry from the index is shown on the screen.The display is circular in that after the last entry in the index isdisplayed, the first one will again be displayed. At any time duringthis procedure, the user can hit "Escape: in which case control isreturned to the main program loop via ○2 .

In any event due to the fact that this subroutine was invoked, the localuser must select the "Save" routine again in order to store the graphicand thus if the index is not full, and if the name was not found in theindex or given that the name was found and the user indicated that hewishes to replace the picture with a new version, then the first portionof the picture which was previously saved that would have been displayedin the menu area is retrieved on the screen and then a binary "Save"routine that is included in the language being used is invoked to copythe contents of the video display buffer to the disk file named by theuser. This is indicated by step 174. After this has been completed, theindex is updated as indicated by step 176 and the revised index iswritten back to the storage of the dual disk drive unit 26, and controlreturns to the main loop via ESCAPE #2, i.e. ○2 .

Referring now to FIG. 10, when the local user wishes to transmit anon-screen graphic to a remote user during a teleconference, for example,he selects the "T" mode on his keyboard 21 by pressing the key labeled"T". This is shown by the block 178. A flag is immediately checked todetermine whether or not the Standard Menu (Table II) is currently beingdisplayed on the user screen. If it is it is replaced with a portion ofthe picture that was saved at the time it was previously displayed onthe video display 24. Then control passes to a routine whichaccomplishes the actual transmission of the required graphic to theremote user(s). The first statement in this routine calls for aprocedure 180 which turns off power to the local user's speakerphone 20by way of the multiposition power relay 48 (FIG. 2) and the parallel I/Oport 34. When the speakerphone 20 has been turned off, the transmittersection of the local user's modem 18 is turned back on by sending acommand to that effect to the modem. This is indicated by step 182.After this a signature or "ID" signal is sent out (step 184) whichconsists of a character "T" which is repeated 12 times and serves as asignal to the remote user computers 16 in the network that a picture isabout to be transmitted. It might be recalled that this is thecomplement of the reception of the "T" code referred to above (step 78)

Next a routine is called to construct and transmit the graphic code tothe remote users. This is shown by reference numerals 186 and 188 andcomprises the transmission of 100 individual data segments, each ofwhich consists of two or more alternating lines across the screen, witheach segment being, as noted earlier, proceeded by a segment headerconsisting of five repetitions of a byte containing the number 0 andthen a byte which contains the segment number ranging from 1 to 100.Following this the data in the segment is compressed e.g. using bytepairs, each byte pair indicating (a) one of the four colors and (b) thenumber of continuous pixels of that color. A new byte pair is created ateach color change until all pixels in the segment have been describedand transmitted. After all the byte pairs for the segment have been sentout, the loop over the segments is incremented and the logic is repeatedfor the next segment. Once all the segments have been scanned,compressed and transmitted, the modem's transmitter is turned off whilekeeping the receiver on as indicated by step 190, following which thelocal user's speakerphone 20 is turned back on as evidenced by step 192and control returns to the main program loop (step 74) where theStandard Menu is displayed (step 72). The control return path is via ○2.

Referring now to FIG. 11, when a "View" command is generated by thelocal user by his entering "V" on the keyboard 21 per step 194 of FIG.11, control transfers to a routine which asks the remote user(s) todisplay a particular graphic which is supposedly on hand in hisrespective dual disk drive unit 26. This procedure first checks to seewhether the local user has supplied a number for the graphic with theview command. If this is not the case, the user is asked by step 196 toenter the name or number of the graphic that is desired. In bothinstances the user can press the "Escape" key and return to the maincontrol loop via ○2 . When the name or number has been entered, theindex is scanned to see whether or not the graphic required exists. Thisis shown by the query 198. If it does not, the user is asked whether hewants to review the index list as shown by the query 200. If the answeris in the negative or the "Escape" key has been hit, the routine abortsand control returns back to the Standard Menu display (step 72) and themain program loop 74 via ○2 . A "YES" response initiates a picture bypicture listing (step 201) which permits the user to select the numberof the desired graphic as shown by the block 202, whereupon the localuser's speakerphone is turned off by power relay 48 as shown by step206. Next a "V" code is transmitted by the local user (step 208) to theremote user(s) and which consists of an ID signal comprised of a groupof characters beginning with 10 "V"s followed by three bytes containingthe number of the graphic and the data set name for the graphic. Thisgroup of characters is transmitted twelve times to the input buffer ofremote user modems 18 with brief pauses in between and comprises theopposite sequence to receive the "V" code described with reference tostep 76 of FIG. 3. The graphic to be viewed on remote user video displayunit 24 is simultaneously read to the local user video display unit 24per step 210, whereupon the local user's modem transmitter is turnedoff, the speakerphone is turned back on as evidenced by the blocks 212and 214 and control returns to the main program loop (step 74) via ○2 .

With reference to FIG. 12, if the "Next" picture in the index of storedgraphics is desired the local user enters "N" on the keyboard 21 asindicated by step 216 which is followed by an increment of the indexpointer (step 218) whereupon the "View" routine is again executed perstep 220 with a return to the main program loop by means of an escapevia ○2 . This escape is also initially available upon selection of the"Next" mode as indicated at step 216.

In the event that the "Previous" picture or graphic is desired, it ishandled substantially in the same manner in which the previouslydescribed "Next" routine is accomplished and, as shown in FIG. 13,requires selection of the "P" mode on the local user keyboard bypressing the "P" key. This is shown by block 222 which is followed by adecrement of the index pointer to the previous graphic as shown by step224, whereupon the "View" routine is again called as shown by step 226with a return to the main program loop via ESCAPE #2. It should be notedthat the "View" command as well as the "Next" picture and "Previous"picture depends for their success upon the fact that all of the remoteusers in the network of the system shown in FIG. 1 already have therequired graphics stored in their respective dual disk drive units 26.

The local user can initiate an "Index" command as one of the StandardMenu options and as FIG. 14 indicates by entering an "I" on the localuser keyboard 21. This is shown as step 228 which also includes anescape via ○2 . Thereafter the CRT of the local user's video displayunit 24 is cleared (step 229) followed by a retrieval and display of theindex stored in the disk drive unit 26 as evidenced by step 230. With adisplay of the index, the local user is given the option of nowrenumbering or deleting graphics. If renumbering is desired, the localuser next presses the "R" key on the keyboard (step 231). The local userthen enters the number of the "old" picture currently being displayed(step 232) followed by an entry of the "new" number which is desired(step 233). A change entry subroutine is now run wherein the index ischecked to see whether the entry the user has made is valid and if thenumber for the old graphic does not correspond to a line which storesthe picture data, then the user input is ignored and the subroutine isrepeated for pairs of old and new numbers. Similarly, if the entryobtained for the line which is to contain the picture now alreadycontains a graphic then the input is ignored and the local user is askedagain to enter that number. Once valid values have been obtained for theold number and the new number, the order of the index is changed (step234) simply by moving the line from its current position to a new one,and the index is thereafter redisplayed. At that point, the subroutinestarts over again, requesting the user to enter another "old" number;however, when desirable, the local user can hit the "Escape" key on thekeyboard 21.

If, on the other hand, the local user wishes to delete a graphic, hefirst enters "D" on the keyboard as indicated by step 235 and thenenters the number of the picture that he wishes to delete (step 236).The number is checked to see if it appears in the index by the query237. If the answer is negative, the subroutine loops back to step 236.An affirmative answer results in the user being asked whether or not hewishes to delete that particular picture (step 238). If the user repliesin the negative, there is a return to step 236. If the user answers inthe affirmative, however, the picture is then deleted as from the diskin the disk drive 26 as indicated by step 239 and that line of the indexis replaced with blanks. When the picture has been deleted, thesubroutine reverts back to the selection steps 231 and 235. Also anescape back to step 235 can be made at the entry (step 236) of thepicture number to be deleted. Each time the local user successfullydeletes a graphic, the index file is rewritten to the disk drive unit 26so that it will always contain accurate information.

Option No. 8 of the Standard Menu as shown in Table II comprises a localuser's selection of a Companion Graphics program e.g. "Army Graphics"and furthermore is identical to option No. 3 of the Main Menu. This dualoption is shown in FIG. 15 and involves first activating the "A" key onthe keyboard 21 as evidenced by step 240, whereupon an internal flag ischecked to see whether or not the Main Menu or the Standard Menu isbeing displayed. If the initial five Main Menu choice of Table I isbeing displayed, as indicated by reference numeral 241, then all filesare closed (step 242) and the graphics program is run per step 243. Ifon the other hand the Standard Menu is displayed as indicated at 244, awarning (step 245) is displayed to the local user indicating that hisspeakerphone 20 must be left off the hook in order to maintain aconference connection. Then the local user is asked (query 246) if, inlight of this fact, he still wishes to proceed to the Companion Graphicsprogram. If the local user enters "No", the command is aborted andreturn or escape to the main control loop (step 74) is effected via ○2 .If the reply is in the affirmative, the phone line is dropped per step247, all files are kept open per step 248 but control is transferred tothe Companion Graphics program as indicated by step 250.

Next if the local user presses the "Tab" key on the keyboard 21, asindicated by reference numeral 252 of FIG. 16, an internal flag,indicating whether or not a menu is being displayed, is switched, i.e.,if the flag was set to be "true", it would be set to "false" and viceversa. If a menu was being displayed in addition to setting the flag to"false", a routine is called which retrieves the stored portion of thepicture in the main area and places it on the CRT of the local user'svideo display unit 24. If a menu is not being displayed, then after theflag is switched, the menu is printed on the CRT. This is indicated bystep 254.

Finally, the "Escape" option as shown by FIG. 17 involves hitting the"Escape" key on the keyboard 21 within any one of the Index (FIG. 14),Previous (FIG. 13), Next(FIG. 12), View (FIG. 11), Transmit (FIG. 10),Save (FIG. 9) or Use (FIG. 8) operational modes of the Standard Menuoptions as indicated by step 256. This causes the Standard Menu (FIG. 2)to be again displayed (step 258). Now if the "Escape" key is againpressed or hit at any time when the Standard Menu is being displayed,the program will revert back to a display of the Main Menu as shown bystep 260.

As indicated earlier, the main program loop comprises a sequence ofinstructions which continually check to see if the local user haspressed any keys on the keyboard 21 or checks the input buffer of thelocal user's modem 18 to see if any characters have been received from aremote user, indicating that the local user is in receipt of either a"V" code or a "T" code and executes which routine is called for and oncethe routine has been completed, resumes its checking of both thekeyboard and the modem.

Thus dial-up audiographic communication is provided between a pluralityof participants in a conference call connection while using a singleexisting voice grade telephone line. The apparatus of the subjectinvention is designed to be unobtrusively "on" during a conference callbetween the parties and is silent unless ordered to transmit, in whichcase, for example, graphics are retrieved from computer storage and sentsimultaneously to all participants at the appropriate moment in aconversation while requiring approximately 40 seconds per graphic,during which conversation inot possible. When desirable, however,graphics may be transmitted prior to the actual telephone conversationand retrieved from each local storage on demand at a rate ofapproximately 7 seconds per graphic.

While there has been shown and described what is at present consideredto be the preferred method and apparatus for practicing the invention,it should be noted that other modifications will readily occur to thoseskilled in the art. Accordingly, it is not desired that the invention belimited to the specific arrangements shown and described, but it isintended to cover all such modifications as fall within the spirit andscope of the invention as defined in the appended claims.

I claim:
 1. An audiographic telephone conference system between aplurality of participants or users, comprising:a plurality of userapparatus, one for each participant, each said user apparatus having asingle respective telephone line for selectively coupling to one or moreother said user apparatus, and wherein each said user apparatus furtherincludes, telephone apparatus; a programmable modem including areceiving section and a transmitting section; a programmable digitalcomputer operable to control the connection of said telephone apparatusand said modem to said respective telephone lines, said computer furtherincluding, operational mode selection means, video display means, datainput means, a memory for storing a computer program and a plurality ofgraphic images fed into said memory by said data input means and meansfor retrieving a selected graphic image from said memory, said memoryfurther including means for storing one or more user viewable graphicimages and a user viewable index file of stored graphic images, andmeans for selectively displaying said graphic images or said index fileon said display means; said computer being operable in accordance withsaid stored computer program to cause said modem receiving section tocontinuously silently monitor telephone communications among theplurality of users without interfering with voice conferencing exceptwhen transmitting to permit operation of said mode selection means to:(i) selectively cause a graphic image locally stored in said memory toboth be displayed by said display means and to be transmittedsimultaneously to all other participants turing a mandatory briefinterruption in voice communication among said users; (ii) receive agraphic image transmitted from other said user apparatus via therespective programmable modems also turing a mandatory briefinterruption in voice communication among said users; and (iii) further,when desirable, switch to a companion graphics program capable of bothaltering existing graphic images and generating new graphic images. 2.The system as definein claim 1 wherein said plurality of participants isa least three, and wherein said user apparatus additionally includesaudio recorder/playback means connected to said telephone line forrecording audiographic information transmitted from another said userapparatus prior to and during a telephone conference between at leastthree of said users.
 3. The system as defined in claim 1 andadditionally including conference call connection means interconnectingsaid plurality of user apparatus by said respective telephone lines andfurther including signal amplifying means for eliminating line dropduring a conference call connection between plurality of said users. 4.The system as defined by claim 1 wherein each said computer controls arespective said modem to transmit and receive exclusively on the sameone half of the telephone line's bandwidth so that graphic data signalscan be transmitted and received over a voice grade telephone line. 5.The system as defined by claim 1 wherein said telephone apparatuscomprises a speakerphone and audio tape recorder/player and additionallyincluding a power relay coupled to said computer for controlling theenergization of said speakerphone and said audio tape recorder/player.6. The system as defined by claim 1 wherein said memory comprises firstmemory means including an internal video display buffer and an externaldisk or tape drive unit for storing information from said display andsaid graphic images, second memory means for storing said computerprogram, and input/output ports, said first and second memory meansbeing coupled to said programmable modem and said telephone apparatus byrespective input/output ports.